NeuroSearch says that its Phase III drug for Huntington disease, Huntexil, not only has symptomatic effects but also slows the underlying disease progression depending on the patients' disease genotype. This analysis comes after the firm reported in February that the treatment significantly improved patients' motor function.

NeuroSearch has filed a patent application covering the ability of Huntexil to slow down the progression of disease in symptomatic patients as well as prevent the occurrence of symptoms in premanifest subjects. The patent application also covers certain compounds in NeuroSearch's pipeline of dopaminergic stabilizers.

The MermaiHD study was a randomized, double-blinded, placebo-controlled Phase III trial conducted at 32 clinical centers across Europe to examine the effects of Huntexil on a number of Huntington disease parameters. Data from the placebo-treated patient group confirmed a strong correlation between the length of the Huntington disease gene and the rate of symptom progression.

The more CAG repeats there are in the gene, the faster is the progression of clinical symptoms. In the Huntexil-treated patients the CAG-dependent rate of progression of motor symptoms as observed in the placebo group was not apparent. The company thus suggests that the drug has the ability to potentially modify the underlying disease progression.

Results reported on February 3 showed that Huntexil met its primary endpoint, improving motor function as well as voluntary and involuntary motor symptoms. At the time the company said that it would initiate discussions with the EMEA and FDA.

NeuroSearch is also evaluating Huntexil in a second randomized and placebo-controlled trial, the HART study, being conducted in the U.S. and Canada in approximately 220 patients with Huntington disease. Patient recruitment in the HART study is still ongoing, and study results are expected in the second half of 2010.